Ck. Lumpkin et al., THE IMPACT OF TOTAL ENTERAL NUTRITION ON DISTRACTION OSTEOGENESIS IN A RAT MODEL, Journal of bone and mineral research, 11(7), 1996, pp. 962-969
Limb lengthening by gradual mechanical distraction, termed distraction
osteogenesis (DO), results in new bone formation. We have developed a
rat tibial model for DO and have proceeded to study the effects of nu
trition on this process. We have combined the intragastric diet delive
ry system of total enteral nutrition (TEN) with DO in the rat model. T
he first study was designed to address the weight loss associated with
DO in dogs and patients. Rats in the chow + DO group lost 10% body we
ight over the 20-day distraction period but gradually gained weight ba
ck to the preoperative level by the end of the 5th week of the hone co
nsolidation period, In contrast, in the TEN + DO group, a weight gain
was recorded during the 20-day distraction phase. A second study was c
onducted to determine the effects of TEN on the rate and histology of
regenerate bone formation. The weight changes replicated those seen in
the first study. Standardized radiographs, taken on day 20, revealed
increases (p < 0.003) in regenerate bone formation in the TEN group wh
en compared with the chow group. Increased numbers of osteoclasts in t
he TEN group may indicate an accelerated entry into the remodeling pha
se of consolidation. Serum IGF-I values, taken at day 20, did not diff
er between the groups. These results demonstrate that the nutritional
support dramatically increased the mineralized bone formed over the 20
-day distraction period.